Set RPM on IH 1660?

Tree-Farmer · Dec 14, 2023

I bought a CaseIH 1660 combine, it's a 1989 and has the International engine.

Everyone says you should run it at full throttle, when I do this, the gauge shows 2350 RPM. That's all I can adjust it to,
that's the max with the lever in the cab.

The manual says, Rated Engine Speed: 2500 RPM and
Governor Engine Speed without load: 2680 to 2740 RPM

Question: Should I ask my mechanic to adjust the engine to get up to 2500RPM?
How would you do this?

Could this be a stretched cable?
Or is there an adjustment on the engine to let it go a little faster?

Also, what does it mean that the governor is set higher?
If it only goes to 2500, how can the governor limit it to 2600?

Thank you!

Bob Bancroft · Dec 14, 2023

Is your alarm going off? My 1660 has the Case/Cummins, but calls for the same speeds. If it slows below 2450, the alarm goes off. The adjustment is on the injector pump, but of course your cable needs to be making enough travel too. My combine, and many others, threw a rod through the side of the block because of those ridiculous speeds. I have mine adjusted so it runs about 2550 wide open no load. It maintains 2450 or more a majority of the time. And I'm careful about only running it wide open under load. If I'm driving down the road, or down a hill, I don't run it wide open, as I won't let it overspeed. As long as you're in the field, with the thresher running, it's not a problem.

tractorsam · Dec 15, 2023

There is a difference between the IH and Cummins engined ones, the earlier Cummins powered units suffered quite a few failures as they couldnt handle the roms that the IH engines could. The slightly later ones were re geared to allow for a reduced engine rpm. On the IH engine version one I would run it to full rpm. The first thing to check is does the cable pull the arm on the injection pump to the stop? If not adjust it and then see what you get before going further.

urbancase · Dec 15, 2023

the comments below are right, my first casih combine 1680 was a 85 i think and had the DT466 and it throwed a rod and it took out the fuel filters that cause a fire and lost the combine, i replaced it with a 92 model 1680 and it did run slower RPM's. it had the 8.3 in it and to me was a better combine, running a slower RPM the way it was geared seemed it didn't load down as bad in heavy crop. sold the 1680 this year and went to 2388 and it night and day to me between the 2 combines. i would look at your cables as i would guess something came lose or cable screeched but it needs to run and the combine designed RPM to be efficient. good luck

Set RPM on IH 1660?

Tree-Farmer

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Bob Bancroft

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tractorsam

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urbancase

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